This folder holds the cron processor: `/cron/cron_exec.php`. This file should be called regularly and automatically in order to execute scheduled tasks.
Currently, you need to refer to your hosting provider in order to set up automatic calls to the jobs inside of this folder.
Depending on how you set up your cron processor, this folder may or may not need to be accessed through the web.
A global overview of the codebase can be found here.